表单验证

<script type="text/javascript" src="system/common/Util.js"></script>

<script language="JavaScript">

function _check(){

var valid = true;

var username = document.getElementById("username");

var password = document.getElementById("password");

var email = document.getElementById("email");

 

if(username.value.Trim() == ""){

window.alert("用户名不能为空!");

username.value="";

username.focus();

valid = false;

return valid;

}

if(CheckIllegalCharacter(username.value.Trim())){

alert("用户名含有非法字符");

valid = false;

return valid;

}

 

if(password.value.Trim().length<4){

window.alert("密码不能为空且长度不能小于4个字符!");

password.value="";

password.focus();

valid = false;

return valid;

}else{

var idx = email.value.Trim().indexOf('@');

if(idx<=0 || idx==email.value.Trim().length-1){

alert("Email地址格式不合法!");

email.focus();

valid = false;

return valid;

}

}                                                                                                             //window.alert(username.value.Trim().TagTrim().length);  

//window.alert(password.value.Trim().length);  

//window.alert(email.value.Trim().length);  

if(valid){

   document.myform1.submit();

}

}

</script>

 

-------------------------------------------------------------------

<form action="http://www.baidu.com" name="myform1" onsubmit="return _check()">
   username:<input type="text" id="username" name="username"><br>
   password:<input type="password" id="password" name="password"><br>
   email:<input type="text" id="email" name="email"><br>
   <input type="submit" name="tijiao"><br>
</form>

<!--EndFragment-->